Ultrasonic bath to increase tissue perfusion

ABSTRACT

The present invention describes a method of using an ultrasonic bath to enhance tissue perfusion, enhance the development of collateral blood vessels and/or enhance collateral circulation in an extremity in need thereof. Also described is an ultrasonic bath for the inventive method.

FIELD OF INVENTION

This invention relates to a method for using an ultrasonic bath to applytherapeutic ultrasonic energy to enhance tissue perfusion and collateralcirculation and an apparatus for the same.

BACKGROUND

All publications herein are incorporated by reference to the same extentas if each individual publication or patent application was specificallyand individually indicated to be incorporated by reference. Thefollowing description includes information that may be useful inunderstanding the present invention. It is not an admission that any ofthe information provided herein is prior art or relevant to thepresently claimed invention, or that any publication specifically orimplicitly referenced is prior art.

Peripheral Vascular Disease (“PVD”), also referred to as PeripheralArterial Disease (“PAD”), is a general term for diseases caused byocclusion or obstruction of peripheral arteries. PVD is a common diseaseaffecting numerous patients that may lead to morbidity and suffering.The occlusion of peripheral arteries via the processes ofatherosclerosis, inflammatory response, embolism, thrombus formation anddiabetes mellitus may all result in PVD. PVD may cause acute or chronicischemia in the surrounding tissues, particularly in an extremity of theaffected person. The acute or chronic ischemia may result in pain in theextremity (e.g., claudication), loss of sensation in the extremity,sores, wounds or ulcers that heal slowly or not at all, and tissue lossin the affected extremity. Ischemia is characterized by an absolute orrelative shortage of blood supply to a tissue as a result of constrictedor blocked blood vessels supplying the tissue.

The technology available to treat ischemia in an extremity includesinvasive surgical arterial bypass operations, peripheral arterialballoon angioplasty and stent placement. However, in many patients andespecially in those with diabetes mellitus, the occlusive diseaseaffects small blood vessels that are not amenable to mechanicalrevascularization. Current technology tends to have limited long termsuccess with high recurrence rates. Medical therapy is also available;however, the benefit is limited. The most severe cases requireamputation of the extremity.

Thus, there is a need in the art for a method and a device fornoninvasive treatment of ischemia and/or PVD. Further, there is a needfor technology to enhance perfusion to the extremities, to enhance abody's ability to develop collateral blood vessels and to enhancecollateral circulation.

SUMMARY OF THE INVENTION

The following embodiments and aspects thereof are described andillustrated in conjunction with compositions and methods which are meantto be exemplary and illustrative, not limiting in scope.

The present invention describes a method for enhancing tissue perfusion,enhancing development of collateral blood vessels and/or enhancingcollateral circulation in an extremity in need thereof, comprising:providing an ultrasonic bath; placing a subject's extremity in need oftreatment in the ultrasonic bath; and using the ultrasonic bath to applyultrasonic energy to enhance tissue perfusion, develop collateral bloodvessels and/or enhance collateral circulation. The method may furthercomprise applying heat to the extremity. In various embodiments, theextremity in need of treatment may be selected from the group consistingof an arm, hand, finger, leg, foot, toe and combinations thereof.

The ultrasonic bath used by the method may comprise: a basin adapted tohold media and to permit the immersion of an extremity; and one or moreultrasonic transducers to generate and transmit ultrasonic energy to thesubject's extremity. In one embodiment, the basin may be about 20 inchesin length, about 12 inches in width and about 40 inches in depth. In oneembodiment, the ultrasonic bath may further comprise an inlet, an outletor both. In another embodiment, the ultrasonic bath may further comprisea heating element. In another embodiment, the ultrasonic bath mayfurther comprise an ultrasonic transducer control unit.

In various embodiments, the ultrasonic energy applied to the extremitymay be at a frequency of about 18 kHz to about 3 mHz. In particularembodiments, the ultrasonic energy applied to the extremity may be at afrequency of about 19 kHz to about 40 kHz. In other embodiments, theultrasonic energy may be at a power level of about 0.01 watt per cm² toabout 20.0 watts per cm². In particular embodiments, the ultrasonicenergy may be at a power level of about 0.25 watt per cm² to about 5.0watts per cm². In one particular embodiment, the energy may be at apower level of about 1 watt per cm².

In one embodiment, using the ultrasonic bath may comprise applyingultrasonic energy for at least five minutes. In another embodiment,using the ultrasonic bath may comprise applying the ultrasonic energyfor up to 90 minutes. In another embodiment, using the ultrasonic bathmay comprise serial treatments for the extremity.

In another embodiment, the method may further comprise applying heat tothe extremity.

The present invention also describes an ultrasonic bath for enhancingtissue perfusion, enhancing development of collateral blood vesselsand/or enhancing collateral circulation in an extremity in need thereof,comprising: a basin adapted to hold media and to permit the immersion ofan extremity; and one or more ultrasonic transducers to generate andtransmit ultrasonic energy to the subject's extremity. The basin may beabout 20 inches in length, about 12 inches in width and about 40 inchesin depth. In various embodiments, the one or more ultrasonic transducersmay be configured to generate and transmit ultrasonic energy at afrequency of about 18 kHz to about 3 mHz. In particular embodiments, theone or more ultrasonic transducers may be configured to generate andtransmit ultrasonic energy at a frequency of about 19 kHz to about 40kHz. The one or more ultrasonic transducers may be configured togenerate and transmit the ultrasonic energy at a power level of about0.01 watt per cm² to about 20.0 watts per cm². In particularembodiments, the one or more ultrasonic transducers may be configured togenerate and transmit the ultrasonic energy at a power level of about0.25 watt per cm² to about 5.0 watts per cm². In one particularembodiment, the one or more ultrasonic transducers may be configured togenerate and transmit the ultrasonic energy at a power level of about1.0 watts per cm².

The ultrasonic bath may further comprise an inlet, an outlet or both. Inanother embodiment, the ultrasonic bath may further comprise a heatingelement. In another embodiment, the ultrasonic bath may further comprisean ultrasonic transducer control unit.

Other features and advantages of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings, which illustrate, by way of example, variousfeatures of embodiments of the invention.

BRIEF DESCRIPTION OF THE FIGURES

Exemplary embodiments are illustrated in referenced figures. It isintended that the embodiments and figures disclosed herein are to beconsidered illustrative rather than restrictive.

FIG. 1 depicts a basin of an ultrasonic bath in accordance with anembodiment of the present invention.

FIG. 2 depicts an ultrasonic bath with a subject's leg immersed in thebasin in accordance with an embodiment of the present invention.

FIG. 3 depicts an exterior view of an ultrasonic bath in accordance withan embodiment of the present invention.

FIG. 4 depicts a partial view ultrasonic bath with an ultrasonictransducer underneath the basin in accordance with an embodiment of thepresent invention.

DESCRIPTION OF THE INVENTION

All references cited herein are incorporated by reference in theirentirety as though fully set forth. Unless defined otherwise, technicaland scientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs. Singleton et al., Dictionary of Microbiology and MolecularBiology 3^(rd) ed., J. Wiley & Sons (New York, N.Y. 2001); and March,Advanced Organic Chemistry Reactions, Mechanisms and Structure 5^(th)ed., J. Wiley & Sons (New York, N.Y. 2001).

One skilled in the art will recognize many methods and materials similaror equivalent to those described herein, which could be used in thepractice of the present invention. Indeed, the present invention is inno way limited to the methods and materials described. For purposes ofthe present invention, the following terms are defined below.

“Extremity” as used herein refers to a limb of the body. Examplesinclude but are not limited to arms, hands, fingers, legs, feet andtoes.

“Extremity in need of treatment” as used herein refers to an extremitythat is in need of treatment to enhance tissue perfusion, to enhance abody's ability to develop collateral blood vessels and/or to enhancecollateral circulation.

“Media” as used herein refers to liquid, semi-solid (e.g., gel), orsolid (e.g., small beads) substances capable of transferring ultrasonicenergy from an ultrasonic transducer to an extremity and that willsurround the extremity. Examples of media include but are not limited towater, including salt water, sterile water, and deoxygenated water. Inembodiments wherein salt water is used, the concentration of salt may beany appropriate concentration; for example, about 0.25% to about 10%.

Embodiments of the present invention provide for methods and apparatusesfor using ultrasonic energy to enhance collateral circulation andthereby enhance tissue perfusion.

The inventors have shown herein that ultrasound exposure through a waterbath to an extremity increases tissue perfusion in the tissue of theextremity. The increase in tissue perfusion was found to be independentof a temperature increase in the water bath. While not wishing to bebound by any particular theory, the inventors believe that the enhancedtissue perfusion is due, in part, to mechanical vibration. Furthermore,the inventors have previously shown that ultrasound increases theexpression and activity of endothelial nitric oxide synthase (“eNOS”)and inducible nitric oxide synthanse (“iNOS”). (See Atar et al.,“Low-frequency ultrasound increases activity and tissue content ofnitric oxide synthase in acute limb ischemia in rabbits.” World Congressof Cardiology 2006, Barcelona Spain. P595.) The increased expression ofthese enzymes, particularly eNOS, corresponds to an increase in therelease of nitric oxide, also known as endothelium derived relaxingfactor (“EDRF”), within the tissue's blood vessels. Nitric oxide is apowerful biologic signaling molecule, which acts as a vasodilatorrelaxing the smooth muscle surrounding arterial blood vessels. Thedilation of these arterial blood vessels increases the blood flow in thevessel and, as a result, in the surrounding tissue. Moreover, nitricoxide release is also linked to the formation and growth of new bloodvessels in tissue. Accordingly, application of ultrasonic stimuliincreases the collateral circulation and perfusion in ischemic tissues.The inventors also believe that increases in temperature associated withultrasound may further enhance tissue perfusion.

Application of ultrasound with a hand-held transducer is limited due tothe narrow field of application, which makes application of ultrasoundto an entire extremity difficult and time consuming. Moreover, hand-heldtransducers are likely ineffective in delivering uniform increase inblood flow to the extremity.

As such, various embodiments of the present invention provide for anultrasonic bath for using ultrasonic energy to enhance tissue perfusion,to enhance the body's ability to develop collateral blood vessels and/orto enhance collateral circulation in an extremity in need thereof. Theultrasonic bath may comprise a basin configured with one or moreultrasonic transducers to generate and transmit ultrasound energy to anextremity, wherein the basin is adapted to hold media and to permitimmersion of an extremity. The ultrasonic bath may further comprise atransducer control unit to control the amplitude, frequency, powerand/or duration of ultrasonic energy. The ultrasonic bath may alsofurther comprise an inlet and/or an outlet to fill the basin with mediaor to drain the basin of the media. In a particular embodiment, theinlet and outlet may be the same element on the ultrasonic bath to servea dual purpose.

The basin may be made from any appropriate material known in the art. Inone embodiment, the basin may be made of stainless steel. The basin maybe any suitable size and shape that permits the immersion of anextremity. In various embodiments, the size and shape of the basin maybe configured particularly for use with a particular extremity. In oneparticular embodiment, the basin may be about 20 inches in length, about12 inches in width and about 40 inches in depth. The basin size of thisembodiment may be particularly useful for immersion and treatment of aleg. In another particular embodiment, the basin is adapted to permitthe immersion of an entire extremity.

In various embodiments, the ultrasonic transducer may be adapted togenerate and transmit ultrasonic energy at a frequency of about 18 kHzto about 3 mHz. In some embodiments the frequency may be about 19 kHz toabout 40 kHz. In other embodiments, the ultrasonic transducer may beadapted to generate and transmit a power output of about 0.01 watt percm² to about 20.0 watts per cm². In particular embodiments, theultrasonic transducer may be adapted to generate and transmit a poweroutput of about 0.25 watt per cm² to about 5.0 watts per cm². In oneparticular embodiment, the power output may be about 1 watt per cm². Themedia placed in the basin allows for uniform transmission of ultrasonicenergy from the ultrasonic transducer to the extremity that is immersedin the media and surrounded by the media.

In a further embodiment, the basin may further comprise a heatingelement o heat media that is placed into the basin. In one embodiment,the ultrasonic transducer may also be used as a heating element by itstransfer of ultrasound energy into the media. In another embodiment, theheating element may be a separate element to provide heat to the media.

Additional embodiments of the present invention provide for methods ofusing ultrasonic energy to enhance tissue perfusion, to enhance thebody's ability to develop collateral vessels, and/or to enhancecollateral circulation in an extremity need thereof. The methodcomprises providing an ultrasonic bath as described herein, placing anextremity in need of treatment into the ultrasonic bath and using theultrasonic bath to apply ultrasonic energy to the extremity. In oneembodiment, the extremity in need of treatment is placed in theinventive ultrasonic bath and ultrasonic energy is applied to theextremity for at least 5 minutes. In another embodiment, the extremityin need of treatment is placed in the inventive ultrasonic bath andultrasonic energy is applied to the extremity for up to 90 minutes. Theuse of a lower power level may allow for a longer period of treatment.Thus, in some embodiments, treatment for more than 90 minutes may beperformed. In other embodiments, the extremity in need of treatment isplaced in the ultrasonic bath and ultrasonic energy is applied to theextremity for about 15, 30, 45, 60, or 75 minutes. One of skill in theart will be able to determine the appropriate period of treatment. Infurther embodiments, serial treatments for the extremity in need oftreatment may be performed to enhance tissue perfusion, to enhance thebody's ability to develop collateral vessels, and/or to enhancecollateral circulation in an ischemic extremity. For example, theinventive ultrasonic bath may be provided to a patient for home use andthe patient may be instructed to use the ultrasonic bath several times aday (e.g., four times a day). In other embodiments, a patient may visitan outpatient facility to receive the treatment using the ultrasonicbath and thus treatment may be one or more times per week (e.g., onceper week, three times per week, five time per week). One of skill in theart will be able to determine the length, number, and frequency oftreatments that are appropriate for an extremity in need of treatment.Factors to consider may include but are not limited to the subject'sage, health, extent of arterial occlusion, degree of the peripheralarterial disease, degree of the ischemia, and energy level of theultrasonic bath.

In a further embodiment, the method may further comprise the applicationof heat to the extremity. Examples of appropriate temperatures of heatinclude but are not limited to from room temperature (e.g., about 20°C.) to a temperature that does not cause a high level of discomfort orburns to the extremity (e.g., about 43° C. to 48° C.). In variousembodiments, the temperature may be about 20° C., 25° C., 30° C., 35°C., 40° C., about 45° C. Application of heat may be performed by heatingthe media in the ultrasonic bath. Heating the media may be performedbefore placing the extremity in need of treatment into the ultrasonicbath or while the extremity in need to treatment is immersed in themedia in the ultrasonic bath. In other embodiments, the application ofheat to the extremity may be performed before the extremity receives theultrasound treatment or after the extremity received the ultrasoundtreatment.

EXAMPLE

The following examples are provided to better illustrate the claimedinvention and is not to be interpreted as limiting the scope of theinvention. To the extent that specific materials are mentioned, it ismerely for purposes of illustration and is not intended to limit theinvention. One skilled in the art may develop equivalent means orreactants without the exercise of inventive capacity and withoutdeparting from the scope of the invention.

Example 1 Transcutaneous Application of Ultrasound and Measurement ofTranscutaneous Oxygen Tension

A transcutaneous oxygen tension monitor was placed on the left extremityand the corresponding right extremity. Measurement of the transcutaneousoxygen tension is a method of evaluating blood flow in settings wheretissue viability and the blood flow are of concern. If thetranscutaneous oxygen tension is too low, a surgeon may decide toamputate the extremity. Since the transcutaneous oxygen tensiondisplayed by the transcutaneous oxygen tension monitor changes veryfrequently, a series of measurements was recorded over a short period oftime (e.g., 10 seconds, 30 seconds, 1 minute, etc.) and the meantranscutaneous oxygen tension was determined and used as it provides abetter indication of the transcutaneous oxygen tension.

The transcutaneous oxygen tension in both the left extremity and thecorresponding right extremity were measured prior to immersing the leftextremity into the ultrasonic bath. The left extremity was immersed inthe apparatus containing water and ultrasound was applied through thewater to the extremity far five minutes. The transcutaneous oxygentension was measured in both the left extremity and the correspondingright extremity after removing the left extremity from the apparatus.Again, a series of measurements was taken and the mean value was used.The right extremity did not receive treatment.

In the treatment group (i.e., left extremities) of 28, 23 showed 7-52%increase in the transcutaneous oxygen tension in the extremity; 2 showeda decrease in the transcutaneous oxygen tension in the extremity; and 1showed no significant change in the transcutaneous oxygen tension in theextremity. In the non-treatment group (i.e., right extremities) of 23,14 showed a 5-70% increase of transcutaneous oxygen tension in theextremity; 5 showed a decrease in the transcutaneous oxygen tension inthe extremity; and 4 showed no significant change in the transcutaneousoxygen tension in the extremity. Although the corresponding rightextremity was not treated, treatment in the left extremity was able toaffect the blood vessels of the corresponding untreated extremity. Thedetails of the tests are summarized in tables 1 and 2.

TABLE 1 Upper Extremities L. arm L. palm L. index R. arm R. palm R.index pre Post pre Post pre Post pre Post pre Post pre Post USD USD USDUSD USD USD USD USD USD USD USD USD Case 1 39 84 115 153 52 163 23 60 71111 74 37 31 74 112 103 55 118 25 58 66 119 59 35 33 92 109 83 50 78 3857 99 120 56 34 40 67 107 75 43 66 44 59 91 114 55 33 45 63 106 68 40 6359 85 117 33 50 64 103 64 36 60 63 84 114 32 49 50 101 69 36 81 58 35 5796 37 55 91 38 Mean 44.3 70.6 104.4 88.0 42.8 89.9 32.5 59.1 82.7 115.861.0 34.1 incre37% incre52% incre45% incre29% Case 2 14 32 77 99 75 77 850 74 77 88 52 32 25 78 92 62 70 9 50 71 76 74 51 21 30 77 88 57 67 1552 73 77 69 51 22 40 65 85 55 63 12 49 75 76 65 49 26 46 58 82 51 59 1854 75 76 62 48 32 50 56 78 49 57 21 59 76 75 58 48 37 50 58 77 46 54 2963 79 74 55 47 40 56 Mean 28.0 41.1 67.0 85.9 56.4 63.9 16.0 53.9 74.775.9 67.3 49.4 incre32% incre22% incre12% incre70% Case 3 38 64 150 15682 94 95 95 153 149 35 44 150 153 70 86 84 99 153 149 42 45 150 152 6779 90 100 153 149 44 50 142 151 64 72 96 114 137 149 48 53 150 150 62 9790 132 151 54 55 150 149 59 88 128 151 56 150 54 59 52 56 Mean 48.1 51.8148.9 151.8 53.8 82.8 92.4 97.7 142.7 149.7 incre7% incre23% incre5%incre5%

TABLE 2 Lower Extremities R. knee R. ankle R. foot L. knee L. ankle L.foot pre Post pre Post pre Post pre Post pre Post pre Post USD USD USDUSD USD USD USD USD USD USD USD USD Case 4 33 73 73 58 11 70 13 15 46 6844 68 38 75 66 56 33 65 38 61 51 47 48 53 75 67 56 40 86 39 66 67 44 4053 74 57 59 35 67 38 27 37 50 73 51 55 37 64 36 55 71 52 53 42 63 38 7041 42 Mean 47.0 73.0 61.0 56.2 33.0 65.8 32.0 15.0 57.7 53.3 45.0 43.5incre35% incre50% Case 5 46 66 51 55 57 62 74 60 40 85 42 68 55 53 47 5440 65 48 30 53 71 48 55 59 60 51 67 53 52 53 73 47 55 65 63 57 71 48 5774 54 56 66 71 47 63 72 51 54 65 57 52.3 70.7 51.0 54.7 57.0 61.7 55.566.8 47.0 53.2 incre26% incre7% incre7% incre17% incre11% Case 6 99 3964 31 21 27 91 55 31 30 92 41 47 30 32 42 81 59 36 38 45 39 29 34 45 7261 30 38 28 29 31 46 62 39 37 47 63 37 37 38 Mean 95.5 41.7 44.5 29.829.5 41.4 81.3 60.0 35.2 37.8 incre29% Case 7 18 54 25 42 33 36 88 58 4558 27 69 18 58 44 45 43 46 19 56 37 61 37 78 39 62 43 41 35 52 31 56 5461 24 79 40 64 34 41 32 53 39 58 57 64 25 79 40 66 27 36 53 50 57 46 6426 81 47 68 36 51 57 55 46 64 56 77 67 58 49 66 Mean 33.3 52.7 34.8 40.335.8 48.5 47.3 56.9 47.7 62.5 32.5 77.2 incre47% incre14% incre26%incre17% incre24% incre58% Case 8 39 71 67 67 64 84 45 70 42 78 57 67 5767 60 68 60 70 46 67 66 74 61 68 62 72 57 65 57 66 45 53 70 74 64 65 6469 58 63 54 63 44 88 69 75 64 65 64 72 58 64 53 61 46 64 67 74 63 65 6773 58 65 52 59 50 68 88 75 63 66 77 59 52 74 72 79 66 Mean 58.8 71.659.7 65.3 56.7 66.0 46.9 69.1 67.7 75.6 62.0 66.0 incre18% incre8%incre14% incre32% incre10% incre6% Case 9 34 53 29 47 43 53 42 55 44 5931 42 48 54 55 56 48 60 31 38 51 53 60 54 51 61 32 34 51 52 61 53 52 6130 31 51 51 60 51 Mean 45.8 58.8 30.6 38.4 48.8 52.6 55.6 53.8 incre22%incre20% incre7% Case 10 65 74 63 58 47 25 68 71 56 50 15 36 68 76 52 5124 45 Mean 67.0 73.7 57.0 53.0 28.7 35.3 incre9% incre19%

Example 2

In accordance with one embodiment of the invention, FIG. 1 depicts a topview of one embodiment of the ultrasonic bath 100. As shown, theultrasonic bath comprises a basin 101, an outlet 102, an ultrasoundtransducer 103 that is underneath the basin 101, heating elements 104that are also underneath the basin 101, and a transducer control unit105.

In accordance with another embodiment of the invention, FIG. 2 depicts asubject's leg 201 placed in the ultrasonic bath 100. The basin 101 and atransducer control unit 105 are also shown.

In accordance with another embodiment of the invention, FIG. 3 depictsan exterior view of an ultrasonic bath 100. An outlet 102 is used todrain the basin after use. A transducer control unit 105 is used tocontrol the amplitude, frequency, power and/or duration of ultrasonicenergy. Also shown is the transducer 103 underneath the basin 101, aswell as heating elements 104 being underneath the basin 101.

In accordance with another embodiment of the invention, FIG. 4 depicts arepresentation of an ultrasonic bath 101, with an ultrasonic transducer103 underneath the basin 101. The cutlet 102 allows for drainage of thebasin. Heating elements 104 are also underneath the basin.

In another embodiment, additional ultrasonic transducers 103 are placedunderneath the basin 101 (not shown). In an alternative embodiment, oneor more transducers 103 are place on the side of the basin (not shown).Alternatively, one or more transducers 103 are immersed in the basin 101(not shown).

Various embodiments of the invention are described above in the DetailedDescription. While these descriptions directly describe the aboveembodiments, it is understood that those skilled in the art may conceivemodifications and/or variations to the specific embodiments shown anddescribed herein. Any such modifications or variations that fall withinthe purview of this description are intended to be included therein aswell. Unless specifically noted, it is the intention of the inventorsthat the words and phrases in the specification and claims be given theordinary and accustomed meanings to those of ordinary skill in theapplicable art(s).

The foregoing description of various embodiments of the invention knownto the applicant at this time of filing the application has beenpresented and is intended for the purposes of illustration anddescription. The present description is not intended to be exhaustivenor limit the invention to the precise form disclosed and manymodifications and variations are possible in the light of the aboveteachings. The embodiments described serve to explain the principles ofthe invention and its practical application and to enable others skilledin the art to utilize the invention in various embodiments and withvarious modifications as are suited to the particular use contemplated.Therefore, it is intended that the invention not be limited to theparticular embodiments disclosed for carrying out the invention.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art that,based upon the teachings herein, changes and modifications may be madewithout departing from this invention and its broader aspects and,therefore, the appended claims are to encompass within their scope allsuch changes and modifications as are within the true spirit and scopeof this invention. It will be understood by those within the art that,in general, terms used herein are generally intended as “open” terms(e.g., the term “including” should be interpreted as “including but notlimited to,” the term “having” should be interpreted as “having atleast,” the term “includes” should be interpreted as “includes but isnot limited to,” etc.).

1. A method for enhancing tissue perfusion, enhancing development ofcollateral blood vessels and/or enhancing collateral circulation in anextremity in need thereof, comprising: providing an ultrasonic bath;placing a subject's extremity in need of treatment in the ultrasonicbath; and using the ultrasonic bath to apply ultrasonic energy enhancetissue perfusion, develop collateral blood vessels and/or enhancecollateral circulation. 2-15. (canceled)
 16. An ultrasonic bath forenhancing oxygen level in an extremity in need thereof, comprising: abasin shaped and sized to hold media and to permit the immersion of theextremity; and one or more ultrasonic transducers configured to generateand transmit ultrasonic energy to the extremity at a plurality offrequencies.
 17. The ultrasonic bath of claim 16, wherein the basin isabout 20 inches in length, about 12 inches in width and about 40 inchesin depth.
 18. The ultrasonic bath of claim 16, wherein the one or moreultrasonic transducers are configured to generate and transmitultrasonic energy at a frequency of about 18 kHz to about 3 mHz.
 19. Theultrasonic bath of claim 16, wherein the one or more ultrasonictransducers are configured to generate and transmit the ultrasonicenergy at a power level of about 0.01 watt per cm² to about 20.0 wattsper cm².
 20. The ultrasonic bath of claim 16, wherein the one or moreultrasonic transducers are configured to generate and transmit theultrasonic energy at a power level of about 0.25 watt per cm² to about5.0 watts per cm².
 21. The ultrasonic bath of claim 16, furthercomprising an inlet, an outlet or both.
 22. The ultrasonic bath of claim16, further comprising a heating element.
 23. The ultrasonic bath ofclaim 16, further comprising an ultrasonic transducer control unit. 24.The ultrasonic bath of claim 23, wherein the transducer control unit iscoupled to the one or more ultrasonic transducers operative toselectively control the frequency and duration of the ultrasonic energytransmitted to the extremity during operation.
 25. The ultrasonic bathof claim 23, wherein the transducer control unit is configured to allowfor adjusting the frequency and duration of the ultrasonic energytransmitted to the extremity during operation.
 26. The ultrasonic bathof claim 16, wherein the extremity is selected from the group consistingof an arm, hand, finger, leg, foot, and toe.
 27. The ultrasonic bath ofclaim 16, further comprising the coupling media, wherein the couplingmedia comprises a saltwater solution having a salt concentration ofbetween 0.25% and 10%.
 28. The ultrasonic bath of claim 16, wherein theone or more ultrasonic transducers are configured to generate andtransmit ultrasonic energy at a frequency of about 18 kHz to about 3MHz.
 29. The ultrasonic bath of claim 16, wherein the one or moreultrasonic transducers are configured to generate and transmitultrasonic energy at a frequency of about 19 kHz to about 40 KHz. 30.The ultrasonic bath of claim 16, further comprising the coupling media,wherein the coupling media comprises a semi-solid or a solid.
 31. Theultrasonic bath of claim 16, further comprising the coupling media,wherein the coupling media comprises a gel.
 32. The ultrasonic bath ofclaim 16, further comprising the coupling media, wherein the couplingmedia comprises small beads.
 33. A method for enhancing oxygen level inan extremity in need thereof, comprising: providing a source ofultrasonic energy; and applying ultrasonic energy at a frequency ofabout 18 kHz to about 3 MHz and at a power level of about 0.01 watt percm² to about 20.0 watts per cm² to the extremity, wherein the extremityis surrounded by media, to enhance the oxygen level in the extremity.34. The method of claim 33, wherein the extremity is an ischemicextremity.